☣️ UN 1393 • CLASS 4
UN 1393 — Alkaline earth metal alloy, n.o.s.
Placard: Dangerous When Wet. ERG Guide 138. Training/quick-reference only — use current ERG + SOP/SOG for incident-specific actions.
🚒☣️
⚠️ This page is a quick-reference aid. For real incidents: stage upwind, isolate, deny entry, request Hazmat early, and consult the current ERG + SOP/SOG.
Alkaline earth metal alloys, such as UN 1393, are highly reactive with water, producing flammable gases and heat. This can lead to spontaneous ignition and explosion.
Hazard overview: UN 1393 produces flammable gases on contact with water and may ignite on contact with water or moist air. The reaction intensity depends on the specific metals present in the alloy.
Response guidance: In case of emergency, isolate the spill area immediately and prevent moisture contact. Use dry sand, dry chemical powder, or soda ash to extinguish fires, but avoid using water or foam.
Advertisement
UN 1393 Quick Details
UN 1393
Product name: Alkaline earth metal alloy, n.o.s.
DOT Class: 4
Placard type: Dangerous When Wet
ERG Guide: 138 (check current ERG)
Initial isolation: ERG 138: Isolate spill 25m (75 ft) all directions. For large spills isolate 50m (150 ft). If water-reactive fire, isolate 800m (0.5 miles) downwind.
Common Hazards of UN 1393
- Produce flammable gases on contact with water.
- May ignite on contact with water or moist air.
- Some react vigorously or explosively on contact with water.
- May be ignited by heat, sparks or flames.
- May re-ignite after fire is extinguished.
- Some are transported in highly flammable liquids.
- Runoff may create fire or explosion hazard.
- Inhalation or contact with vapors, substance or decomposition products may cause severe injury or
Chemical Identity & Physical Properties
UN 1393 is a metallic solid alloy, typically gray to silver in color, with a physical appearance that varies depending on the specific alkaline earth metals present.
| Also known as | Alkaline earth metal alloy NOSGroup 2 metal alloyBeryllium-magnesium-calcium alloyReactive metal alloy |
| Appearance | Metallic solid alloy, typically gray to silver in color. Physical appearance varies depending on specific alkaline earth metals present (beryllium, magnesium, calcium, strontium, barium). Odorless in dry state. |
| Flash Point | Not applicable (reactive metal solid) |
| Boiling Point | Not applicable (varies by alloy composition, typically >1000C) |
| Vapor Density | Not applicable (solid) |
| Water Reactivity | Reacts with water producing flammable hydrogen gas and heat. May ignite spontaneously on contact with moisture or humid air. Reaction intensity depends on specific metals present. |
Chemical details are general reference only. Always verify with current SDS, ERG, and SOP/SOG.
Fireground Response Guidance — UN 1393
Extinguishing Media
Dry sand, dry chemical powder, soda ash. DO NOT use water, foam, CO2, or halogenated agents.
PPE Requirements
⚠️ Level B minimum with full face SCBA. Chemical-resistant suit for spill response. Keep material dry at all times. Avoid moisture contact.
Wear Level B minimum personal protective equipment (PPE) with a full face self-contained breathing apparatus (SCBA) and a chemical-resistant suit for spill response.
Isolation & Evacuation
ERG 138: Isolate spill 25m (75 ft) all directions. For large spills isolate 50m (150 ft). If water-reactive fire, isolate 800m (0.5 miles) downwind.
Always confirm protective actions with the current edition of the Emergency Response Guidebook (ERG Guide 138).
First Actions for a UN 1393 Incident
- Keep unauthorized personnel away.
- Stay upwind, uphill and/or upstream.
- Ventilate closed spaces before entering, but only if properly trained and equipped.
- Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
- Consider initial downwind evacuation for at least 300 meters (1000 feet).
Advertisement
📋 Copy & Share Field Card
UN 1393 — Alkaline earth metal alloy, n.o.s.HAZMAT RADIO NOTE — UN 1393
Product: Alkaline earth metal alloy, n.o.s.
Class 4 / Dangerous When Wet / ERG 138
PPE: Level B minimum with full face SCBA. Chemical-resistant suit for spill response. Keep material dry at all times. Avoid moisture contact.
ISOLATION: ERG 138: Isolate spill 25m (75 ft) all directions. For large spills isolate 50m (150 ft). If water-reactive fire, isolate 800m (0.5 miles) downwind.
ACTION: Stage upwind · Isolate · Deny entry · Request HazmatRADIO
Use for: Quick radio or face-to-face size-up. Short, structured, field-ready.
=== IC HAZMAT BRIEFING ===
UN 1393 — Alkaline earth metal alloy, n.o.s.
Class: 4 | Placard: Dangerous When Wet | ERG Guide: 138
Appearance: Metallic solid alloy, typically gray to silver in color. Physical appearance varies depending on specific alkaline earth metals present (beryllium, magnesium, calcium, strontium, barium). Odorless in dry state.
Water Reactivity: Reacts with water producing flammable hydrogen gas and heat. May ignite spontaneously on contact with moisture or humid air. Reaction intensity depends on specific metals present.
Extinguishing: Dry sand, dry chemical powder, soda ash. DO NOT use water, foam, CO2, or halogenated agents.
PPE: Level B minimum with full face SCBA. Chemical-resistant suit for spill response. Keep material dry at all times. Avoid moisture contact.
Isolation: ERG 138: Isolate spill 25m (75 ft) all directions. For large spills isolate 50m (150 ft). If water-reactive fire, isolate 800m (0.5 miles) downwind.
— Key Hazards —
• Produce flammable gases on contact with water.
• May ignite on contact with water or moist air.
• Some react vigorously or explosively on contact with water.
— First Actions —
• Keep unauthorized personnel away.
• Stay upwind, uphill and/or upstream.
• Ventilate closed spaces before entering, but only if properly trained and equipped.
• Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters
SOURCE: allfirefighter.com/hazmat/un/alkaline-earth-metal-alloy-un-1393 | Always use current ERG + SOP/SOGIC BRIEFING
Use for: Incident command briefing, staging area whiteboard, or pre-entry team brief.
UN1393 Alkaline earth metal alloy, n.o.s. Cls4 ERG138 | allfirefighter.com/hazmat/un/alkaline-earth-metal-alloy-un-1393SMS / 160 CHAR
Use for: Quick text to command or incoming units. Fits in a single SMS.
⚠️ Quick-reference only. Always use current ERG + SOP/SOG for incident-specific actions.
Page: https://allfirefighter.com/hazmat/un/alkaline-earth-metal-alloy-un-1393
Advertisement
Frequently Asked Questions about UN 1393
Yes, UN 1393 can ignite on contact with water or moist air.
No, do not use water or foam to extinguish a UN 1393 fire.
Wear Level B minimum PPE with a full face SCBA and a chemical-resistant suit.
Sources (high level): DOT/PHMSA marking & class concepts + ERG usage principles.
This page does not reproduce ERG guide text—always consult the current ERG for incident-specific protective actions.